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Measuring Research Impact: Journal Impact

Learn how to measure the impact of your research.

Measuring Journal Impact

Journal impact metrics attempt to quantify the importance of a particular journal in its field, usually via an algorithm that takes into account the number of articles published per year and the number of citations to articles published in that journal.  Like author impact measurements, journal impact measures have limitations. Dissatisfaction with existing metrics has contributed to the development of new metrics such that there are now quite a few. While these metrics do tell us something, researchers in a discipline will have the best sense of the top journals in their field.

Boxes on this page include descriptions of the more common journal impact metrics, as well as what tools to use to find the metrics.

Journal Citation Reports via Web of Science

InCites Journal Citation Reports

You can access Journal Citation Reports (JCR), a product of Thomson Reuters, via Web of Science (look for the link JCR link at the top of the page). Published annually, JCR provides a number of journal impact measurements for journals in the sciences and social sciences. Reported metrics include Impact Factor, 5-year Impact Factor, Immediacy Index, and others. Since 2007, JCR has also included Eigenfactor Metrics.

Learn more:

CiteScore journal metrics from Scopus

Sources tab in Scopus

The Sources tab is available via the top menu bar in Scopus. You can search for a particular journal, or browse sources alphabetically or by subject.

Sources search interface in Scopus

Available metrics are CiteScore, SJR, and SNIP.

Google Scholar Metrics

Google Scholar Metrics

Google Scholar Metrics includes a top 100 list of journals for particular subject fields ranked using their 5-year h-index. You can look at top journals in particular subject categories and sub-categories. The underlying data come from Google Scholar. Sections on Metrics, Coverage, and Inclusion tell you more about how the rankings were derived.

Highlights of Journal Metrics

Journal Impact Factor

  • Frequency with which the 'average article' in a journal has been cited in a particular year or other defined time period using data from Journal Citation Reports.
  • The 'classic' Impact Factor uses a 2-year citation window, but a 5-year Impact Factor is also available.
  • Cannot be used to compare journals across disciplines.
  • Available via Thomson Reuters InCites Journal Citation Reports

Eigenfactor and Article Influence Scores

  • Eigenfactor: Measurement of the 'importance' or 'influence' of a journal. Citations from high-quality journals are weighted more than citations from lesser known journals.
  • Article Influence: Calculated by dividing the Eigenfactor by the number of articles published in the journal. 
  • Both scores use a 5-year citation window, use data from Journal Citation Reports, and are meant to adjust for citation differences across disciplines, since different disciplines have different standards for citation and different time scales on which citations occur.
  • FAQs about Eigenfactor and Article Influence Scores.
  • Available on Eigenfactor website, or via Journal Citation Reports.


  • Uses data from Scopus, with a 3-year citation window.
  • CiteScore calculates the average number of citations received in a calendar year by all items published in that journal in the preceding three years. See CiteScore FAQs to learn more.
  • Cannot be used to compare journals across disciplines.
  • Available via Scopus.

SJR (SCImago Journal Rank)

  • Uses data from Scopus, with a 3-year citation window.
  • Weighted by the prestige of a journal. Subject field, quality, and reputation of the journal have a direct effect on the value of a citation. SJR also normalizes for differences in citation behavior between subject fields. 
  • Available on SCImago Journal and Country Rank website, or via Scopus.

SNIP (Source Normalized Impact per Paper)

  • Uses data from Scopus, with a 3-year citation window.
  • Weights citations based on the total number of citations in a given field (subject), which allows you to compare journals across subjects.
  • Available on CWTS Journal Indicators website, or via Scopus.


  • The largest number h such that at least h articles in that publication were cited at least h times each. For example, a publication with five articles cited by, respectively, 17, 9, 6, 3, and 2, has an h-index of 3.
  • Google Scholar Metrics uses the h5-index, which is the h-index for articles published in the last 5 complete years.